btrfs: On error always free subvol_name in btrfs_mount

ebiederm · kdave · commit 532b618bdf23 · 2019-01-30T18:16:47.000+01:00
The subvol_name is allocated in btrfs_parse_subvol_options and is consumed and freed in mount_subvol. Add a free to the error paths that don't call mount_subvol so that it is guaranteed that subvol_name is freed when an error happens. Fixes: 312c89f ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()") Cc: stable@vger.kernel.org # v4.19+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
@@ -1677,6 +1677,7 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 				flags | SB_RDONLY, device_name, data);
 			if (IS_ERR(mnt_root)) {
 				root = ERR_CAST(mnt_root);
+				kfree(subvol_name);
 				goto out;
 			}
 
@@ -1686,12 +1687,14 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 			if (error < 0) {
 				root = ERR_PTR(error);
 				mntput(mnt_root);
+				kfree(subvol_name);
 				goto out;
 			}
 		}
 	}
 	if (IS_ERR(mnt_root)) {
 		root = ERR_CAST(mnt_root);
+		kfree(subvol_name);
 		goto out;
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -1677,6 +1677,7 @@ static struct dentry btrfs_mount(struct file_system_type fs_type, int flags,`
`1677`	`1677`	`flags \| SB_RDONLY, device_name, data);`
`1678`	`1678`	`if (IS_ERR(mnt_root)) {`
`1679`	`1679`	`root = ERR_CAST(mnt_root);`
	`1680`	`+ kfree(subvol_name);`
`1680`	`1681`	`goto out;`
`1681`	`1682`	`}`
`1682`	`1683`
`@@ -1686,12 +1687,14 @@ static struct dentry btrfs_mount(struct file_system_type fs_type, int flags,`
`1686`	`1687`	`if (error < 0) {`
`1687`	`1688`	`root = ERR_PTR(error);`
`1688`	`1689`	`mntput(mnt_root);`
	`1690`	`+ kfree(subvol_name);`
`1689`	`1691`	`goto out;`
`1690`	`1692`	`}`
`1691`	`1693`	`}`
`1692`	`1694`	`}`
`1693`	`1695`	`if (IS_ERR(mnt_root)) {`
`1694`	`1696`	`root = ERR_CAST(mnt_root);`
	`1697`	`+ kfree(subvol_name);`
`1695`	`1698`	`goto out;`
`1696`	`1699`	`}`
`1697`	`1700`